Mountable Fixture for Absorbing Recoil

ABSTRACT

A fixture is provided for supporting load from weapons recoil, being mountable on a flat bed of a road vehicle disposed on ground. The flat bed can receive a weapons mount. The vehicle has longitudinal, lateral and vertical orientations. The fixture includes a box brace, a recoil platform, first and second brackets, first and second beams, first and second posts and a deck. The box brace extends in the lateral direction. The recoil platform is parallel to the brace. The first and second brackets extend from the platform in the longitudinal direction. The beams are disposable parallel to the brace. The beams are translatable in the lateral direction. The first and second posts extend in the vertical direction downward from respective the first and second beams. The deck can receive the weapons mount, and is disposable on the platform and the brackets. The posts are retractable for stowage and extendible for raising the flat bed above the ground.

STATEMENT OF GOVERNMENT INTEREST

The invention described was made in the performance of official dutiesby one or more employees of the Department of the Navy, and thus, theinvention herein may be manufactured, used or licensed by or for theGovernment of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

BACKGROUND

The invention relates generally to vehicular support for a weaponsplatform. In particular, the invention relates to stands withretractable legs for shock absorption while firing.

SUMMARY

Conventional vehicle supports for weapon systems yield disadvantagesaddressed by various exemplary embodiments of the present invention. Inparticular, various exemplary embodiments provide a fixture forsupporting load from weapons recoil, being mountable on a flat bed of aroad vehicle disposed on ground. The flat bed can receive a weaponsmount. The vehicle has longitudinal, lateral and vertical orientations.

In exemplary embodiments, the fixture includes a box brace, a recoilplatform, first and second brackets, first and second beams, first andsecond posts and a deck. The box brace extends in the lateral direction.The recoil platform is parallel to the brace. The first and secondbrackets extend from the platform in the longitudinal direction.

In exemplary embodiments, the beams are disposable parallel to thebrace. The beams are translatable in the lateral direction. The firstand second posts extend in the vertical direction downward fromrespective the first and second beams. The deck can receive the weaponsmount, and is disposable on the platform and the brackets. The posts areretractable for stowage and extendible for raising the flat bed abovethe ground. Other various embodiments alternatively or additionallyprovide for stabilizing legs mounted to the deck.

BRIEF DESCRIPTION OF THE DRAWINGS

These and various other features and aspects of various exemplaryembodiments will be readily understood with reference to the followingdetailed description taken in conjunction with the accompanyingdrawings, in which like or similar numbers are used throughout, and inwhich:

FIGS. 1A and 1B are perspective views of an exemplary platform-carryingtruck;

FIG. 2 is a first perspective view of a platform fixture;

FIG. 3 is a second perspective view of the platform fixture;

FIG. 4 is a detail perspective view of the fixture;

FIG. 5 is a perspective view of an optional wheel mount;

FIG. 6 is a perspective view of a fixture leg;

FIG. 7 is a third perspective view of the platform fixture on the truck;

FIG. 8 is an elevation view of the platform fixture on the truck;

FIGS. 9A and 9B are perspective views of the truck with a base;

FIGS. 10A through 10D are side elevation views of the truck and fixture;and

FIGS. 11A and 11B are rear elevation views of the truck and fixture.

DETAILED DESCRIPTION

In the following detailed description of exemplary embodiments of theinvention, reference is made to the accompanying drawings that form apart hereof, and in which is shown by way of illustration specificexemplary embodiments in which the invention may be practiced. Theseembodiments are described in sufficient detail to enable those skilledin the art to practice the invention. Other embodiments may be utilized,and logical, mechanical, and other changes may be made without departingfrom the spirit or scope of the present invention. The followingdetailed description is therefore, not to be taken in a limiting sense,and the scope of the present invention is defined only by the appendedclaims.

The Naval Surface Warfare Center Dahlgren Division (NSWCDD) has beentasked by the Office of the Secretary of Defense (OSD) to determine thefeasibility of integrating an Enhanced Mortar Targeting System (EMTAS)onto a wheeled tactical platform or truck vehicle. The vehicle'ssuspension supports the recoil of the EMTAS with minor or nomodifications done to the vehicle, which has the capability to store 120mm rounds and extra charges. The vehicle has the means to lift the EMTASoff the vehicle's flat bed and setting the vehicle on the ground ifneeded for firing operation.

The Mobile Modular Weapon Platform Fixture System (MMWPFS) constitutes asystem in which all these components together work in conjunction inunison to absorb extremely high recoil forces generated by the weaponsystem and transmit them to the ground surface without causing damage tothe vehicle, Conventional platforms for a weapon system are availablefor a specific military vehicle but cannot be utilized outside thevehicle, leading to operational damage to vehicles and platformstructure.

FIGS. 1A and 1B show perspective views 100 of an exemplary vehicleassembly disposed on the ground 110 with a compass rose 120 thatindicates longitudinal (x), lateral (y) and vertical (z) directions. Thelongitudinal directional points forward; the lateral direction pointsport and the vertical (or azimuth) direction points upward. The militaryvehicle 130 (e.g., truck) includes a cab 140 (for seating driver and/orpassenger), a truck flat bed 150 and wheels 160. In the assembly, theflat bed 150 includes the Mobile Modular Weapon Platform Fixture System(MMWPFS) or fixture 170.

FIG. 2 shows a perspective view 200 of the fixture 170 as deployed forpositioning on the ground 110. The stand 170 includes a deck 210 withhand rail 220, and is supported by legs 230 and a stand 240. The deck210 includes a plurality of holes along the periphery and as a mesh onthe surface to facilitate attachments of auxiliary equipment. A ladder250 can be connected to enable personnel to climb from the ground 110 tothe deck 210.

FIG. 3 shows a detail perspective view 300 of the fixture 210. The stand240 includes port and starboard lateral posts 310 and 320, each of whichconnects to an extension beam: a fore beam 330 and an aft beam 340. Thestand 240 further includes an attachment plate 350 for mounting to theflat bed 150. The stand 240 optionally includes detachable recoil wheelmounts 360 that attach to the posts 310 and 320 and enable repositioningthe stand 240.

FIG. 4 shows a detail perspective view 400 of the fixture 170 with thestand 240. A box beam brace 410 reinforces longitudinal stabilityagainst sudden forces from weapons firing. The extension beams 330 and340 extend parallel and adjacent to the beam brace 410. A horizontalplate 420 connects the beam brace 410 to a recoil box platform 430 witha damper 435 therebetween. The recoil platform 430 supports the deck210. A pair of longitudinal brackets 440 extend forward (i.e.,perpendicular) from the recoil platform 430 to support a bottom plate445. An extendible slide rail 450 attaches to each bracket 440. For thefixture 170 installed on the vehicle 130, the box brace 410, recoil boxand damper 435 are longitudinally oriented parallel to the lateral (y)direction of the compass rose, and similarly the brackets 440 and rails450 are longitudinally oriented parallel to the longitudinal (x)direction.

Vertical plates 460, 465 and 470 separate the extension beams 330 and340 from the beam brace 410, with springs and dampers therebetween. Forthe fixture 170 connected to the vehicle 130, these plates 350, 460, 465and 470 are perpendicular to the (x) longitudinal direction. A mid-post480 extends downward from the beam brace 410, as the lateral posts 310and 320 extend from their respective beams 330 and 340. The posts 310,320 and 480 engage the ground 110 by recoil shoes 490 and are lengthwiseadjustable for vertical retraction and extension. The brace 410,platform 430, and beams 330 and 340 have rectangular cross-sections andare composed of steel. The plates 460, 465 and 470 also comprise steel,as do the posts 310, 320 and 480.

FIG. 5 shows a perspective view 500 of the wheel mount 360. An annulartrunk 510 is disposed around the post 310. Lateral branches 520 extendradially from the trunk 510. A stem 530 extends from each respectivebranch parallel to the trunk 510. An axle 540 mounts to each stem 530. Atire wheel 550 that can engage the ground 110 attaches to each axle 540.FIG. 6 shows a perspective view 600 of each leg 230, which is adjustablein length. The leg 230 includes an upper portion 610 and a lower portion620 that telescopes into or out of the upper portion 610. The lowerportion 620 terminates in a pad 630 that engages the ground 110. Thefixture 170 typically includes three legs 230 when deployed. While intransit by the vehicle 130, the legs 230 can be stowed.

FIG. 7 shows a perspective view 700 of the fixture 170 mounted to theflat bed 150 of the vehicle 130. A pivotable mortar base 710 can bedisposed on the deck 210. The base 710 constitutes the turn table forthe EMTAS. FIG. 8 shows a side elevation view 800 of the fixture 170mounted to the flat bed 150. The compass rose 120 shows the orientationof the vehicle 130 facing to the right (and port away from the viewer).The legs 230 and stand 240 elevate the wheels 160 off the ground 110 anddispose the deck 210 a specified vertical distance (e.g., 73.93 inches)therefrom. The deck 210 slideably connects to the flat bed 150 by thebrackets 440 and the recoil platform 430. The legs 230 attach to thedeck 210, or alternatively to the bottom plate 445, by hook brackets 810that can connect and detach as needed.

FIGS. 9A and 9B show perspective views 900 (analogous to FIG. 1B) of thevehicle 130 with the stand 170. FIG. 9A shows the deck 210 including theturn table base 710. FIG. 9B shows such a weapon 910 mounted on a saddle920 disposed on the base 710 that attaches to the deck 210. The mortar910 constitutes, for example, a Recoiling Mortar System RMS6-G or elsean RMS 6-L. FIGS. 10A, 10B, 10C and 100 show side elevation views 1000(analogous to FIG. 8) of the vehicle 130 with the stand 170.

FIG. 10A shows the fixture 170 attaching to the vehicle 130 with posts310, 320 and 480 retracted for road transport. FIG. 10B shows the posts310, 320 and 480 extended and the wheels 160 elevated above the ground110. FIG. 10C shows the legs 230 engaged between the stand 210 and theground 110, and the ladder 250 installed. FIG. 10D shows the vehicle 130moving away (i.e., forward) from the fixture 170, as deployed, FIGS. 11Aand 11B show rear elevation views 1100 of the vehicle 130 and thefixture 170, with the compass rose 120 showing the vehicle 130 facingforward away from the viewer. FIG. 11A shows the fixture 170 as stowedfor road transport, with the posts 310, 320 and 480 retracted. FIG. 11Bshows the fixture 170 deployed for shock absorption, with the beams 330and 340 extended outward and the posts 310, 320 and 480 extendeddownward.

The typical setup time when transporting and using the MMWPFS to firethe weapon (e.g., mortar 910) is reduced approximately by half (groundfire or attached to vehicle 130). Also the fixture 170 can be attachedor carried on the rear of a government vehicle for quick transportationand operation for Forward Operating Base (FOB). In view 200, eachindividual post 310, 320 and 480 can be operated manually using handcranks and gears, or else hydraulically or with an electric motor. Thedeck 210 can be pushed in and retracted up by turning the winch on thevehicle 130 such as a jack.

Conventionally, no currently fielded platforms enable a large weaponsystem to: 1) be easily transported on a variety of vehicles; 2) firewhile being transported; and 3) fire from the ground 110 without majoralterations. Conventional systems enable large weapon systems to beeither ground fired or vehicle fired, but not both. The ground firedsystems are also unable to be used while being transported.

Exemplary embodiments enable the weapon system, e.g., mortar 910, to befired from the vehicle 130 during transport without dismounting. Thedeck 210 can be adjusted vertically by approximately 5 inches from theground 110. Whichever weapon system that is integrated addsapproximately 4 feet to each of these values (6 feet from the ground 110or 9 feet from the ground 110 when fired on the flat bed 150 of thevehicle 130. When fired off the rear of the vehicle 130, the fixture 170is able to receive all the recoil force. Analysis was performed on theEMTAS and MMWPFS using the 5-ton truck (M1083) Family Medium TacticalVehicle (FMTV) family. The RMS6-G Recoil Mortar (EMTAS) can be fired offthe fixture or off the top of a flat bed 150 of the vehicle 130.

A Dynamic Finite Element Analysis (FEA) has been performed on the M1083truck to determine whether the vehicle's frame and suspension systemcould withstand the EMTAS or RMS 6L (120 mm Mortar) 40 metric ton recoilforces when fired off the top of the flat bed 150. The analysis showedthat the recoil forces are so strong that the frame structure would bedamaged when fired. Some sort of reinforcement would be necessaryunderneath the weapon system in order to transmit the forces directly tothe ground 110 without depending on the vehicle's structure. Also thereaction of the recoil forces is so rapid that the suspension systemcannot react on time and the shocks of the system would bottom out andsuffer severe damage. A static Finite Element Analysis (FEA) wasperformed on the MMWPFS using the Structural Steel (ASTM-A36) seriessteel, and the results were acceptable. The fixture 170 can withstandapproximately 40 metric tons of recoil forces.

Human system integration provides the hand rail 220 to reduce personnelhazard from falling off the deck 210 and the ladder 250 to enable anoperator to climb onto the deck 210 or the flat bed 150. The deck 210has several hole mounts in order to accommodate any rail or weaponsystem that could withstand the recoil forces when fired therefrom(e.g., 81 mm, 120 mm Mortar, 2.75 rocket motor 19/7 tube launcher, SmallUAV Drone, or else a base as a lookout tower by using armor instead ofthe hand rail 220).

The recoil platform 430 provides spring action to absorb some of therecoil forces transmitted from the weapon (in x, y and z) motion thatare then reduced through recoil containment plates 460, 465 and 470,which are designed to reduce the recoil forces of the weapon 910 asthese forces are transmitted to the ground 110. Within and between theseplates 460, 465 and 470, this recoil containment constitutes an array ofpart working together in unison (e.g., springs, shock absorbers, rubbermounts, etc.) to absorb that vibrational energy. The pair of extendablebeams 330 and 340, splaying in the lateral (y) direction, assist tostabilize the vehicle 130 and the fixture 170 when firing the mortarweapon 910.

A triplet of vertically adjustable recoil posts (i.e., one center 480and two adjacent 310 and 320) level the MMWPFS system. These posts 310,320 and 480 are adjustable to different heights to act as a strongcolumn in transmitting all the recoil forces to the ground 110. Threerecoil shoes 490 receive the recoil forces from the posts 310, 320 and480 and distribute those forces to the ground 110. The three sets ofretractable stabilizer legs 230 and their pads 630 to engage the ground110 provide stability for the MMWPFS and the vehicle 130 in thelongitudinal (x) and lateral (y) directions when the mortar 910 isfired.

A universal mount 710 on the deck 210 with little or no modificationmade to attach and transport the MMWPFS with a Marine (MTVR), Army(FMTV), or Air force vehicle (tri-service). The removable recoil legs230 are used to move the vehicle 130 (short distance), and the MMWPFS ona level ground 110 without a vehicle 130 for easy installation whenattaching to vehicle 130 or to row on to the vehicle platform. TheMobile Modular Weapon Platform System is intended to provide a stand forintegration with an existing military vehicle that would enable theoperation of a weapon system directly from or off from the vehicle, aswell as withstand the weight, and recoil farces of the weapon withoutdamage to platform, weapon system and vehicle structure.

The principal feature of the Mobile Modular Weapon Platform System isthe ability to utilize the mass of the top carriage to help moderatedouble recoil forces. Two recoil systems are involved the primary systemof the gun, which is directly affected by the dynamic of the round andthe secondary system of the top carriage that controls the impetus ofthe primary system. This fixture 170 has the flexibility of being usedwhile mounted directly to varieties of military vehicle 130 and alsoindependently. The fixture 170 can withstand the weight and recoilforces in order to prevent damage to the deck.

While certain features of the embodiments of the invention have beenillustrated as described herein, many modifications, substitutions,changes and equivalents will now occur to those skilled in the art. Itis, therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the embodiments.

What is claimed is:
 1. A fixture for providing load support from weaponsrecoil and mountable on a flat bed of a road vehicle disposed on ground,said flat bed able to receive a weapons mount, said vehicle havinglongitudinal, lateral and vertical orientations, said fixturecomprising: a box brace extending in the lateral direction; a recoilplatform parallel to said brace; first and second brackets extendingfrom said platform in the longitudinal direction; first and second beamsdisposable parallel to said brace, said beams being translatable in thelateral direction; first and second posts extending in the verticaldirection downward from respective said first and second beams; and adeck for receiving the weapons mount, said deck being disposable on saidplatform and said brackets, wherein said posts are retractable forstowage and extendible for raising the flat bed above the ground.
 2. Thefixture according to claim 1, further comprising: a third post extendingin the vertical direction downward from said box brace.
 3. The fixtureaccording to claim 1, wherein each post further includes a shoe forengaging the ground.
 4. The fixture according to claim 2, wherein eachpost further includes a shoe for engaging the ground.
 5. The fixtureaccording to claim 1, further comprising: a plurality of stabilizinglegs attachable to said deck.
 6. The fixture according to claim 5,wherein each leg further includes a pad for engaging the ground.
 7. Thefixture according to claim 1, wherein each post further includes a shoefor engaging the ground.
 8. The fixture according to claim 1, said firstbeam is disposed forward of said box brace, and said second beam isdisposed aft of said box brace.
 9. The fixture according to claim 1,further comprising: a damper disposable between said box brace and saidrecoil platform.
 10. The fixture according to claim 1, furthercomprising: an attach plate for mounting to said flat bed.
 11. Thefixture according to claim 1, further comprising: a wheel mount for eachof said first and second posts.
 12. The fixture according to claim 1,further comprising: a plurality of recoil plates perpendicular to thelongitudinal direction separating said beams and said recoil box fromeach other.
 13. The fixture according to claim 12, further comprising: ahorizontal plate perpendicular to the vertical direction disposed onsaid recoil box, said horizontal plate supporting said brackets.
 14. Thefixture according to claim 12, further including an attachment plateconnecting to one of said plates for mounting to the flat bed.
 15. Thefixture according to claim 1, the weapons mount is a turn table.